The best diagnostic test for anaphylaxis in a child exposed to an allergen 3 hours before arrival to hospital is

Correct Answer: D

Rationale: Plasma tryptase levels peak within 3 hours and are the most reliable diagnostic test for anaphylaxis.

Correct Answer: B

Rationale: Von Willebrand disease causes prolonged bleeding time despite normal platelet count due to defective platelet adhesion from a deficiency in von Willebrand factor.

Correct Answer: B

Rationale: A prolonged prothrombin time unresponsive to vitamin K suggests severe hepatic synthetic dysfunction and is a poor prognostic indicator in fulminant hepatitis.

Correct Answer: C

Rationale: Approximately 30-50% of childhood asthma cases persist into adulthood, depending on factors such as severity, atopy, and environmental exposures.

Correct Answer: A

Rationale: Distributive shock is characterized by severe vasodilation and reduced systemic vascular resistance. Early sepsis leads to endotoxin-induced vasodilation, making it the most common cause of distributive shock.